(1913 – 1997)



  • Institute of Educational Sciences at the University of Geneva (also known as the Institut Jean-Jacques Rousseau)
    • Bachelor’s Degree in Psychology, 1935
    • Ph.D., 1943


  • School Psychologist
  • University of Geneva
    • Laboratory Instructor 1943-1948
    • Professor of Child and Adolescent Psychology 1948-1971
    • Chair of Genetic and Experimental Psychology 1971-1983

Major Contributions

  • Student of and then collaborator with Piaget for 40 years
  • Her work played major role in the cognitive revolution in psychology

Ideas and Interests

Although much of Inhelder’s work would be considered more developmental in nature, there is much overlap into the domain of intelligence. Much of Inhelder’s earlier work, including her dissertation focused on children’s understanding of conservation and concrete operations. During the time when she was collecting data for her dissertation, however, she was working as a school psychologist and had many opportunities to observe and work with mentally retarded children. When working with these children, Inhelder rejected the traditional intelligence test and ingeniously incorporated her work with conservation into assessing the mental capacities of these children. She would evaluate the mentally retarded children with tasks involving the transformation of a ball of clay, the dissolution of sugar, and logical-mathematical composition. Through her analysis of mental retardates, she found that they do indeed follow the same developmental pattern as other normally functioning children, just at a slower rate.

Another one of Inhelder’s important contributions is her involvement in the discovery of another stage of development – formal operations. Inhelder deserves much of the credit for initiating the investigation of the transition of though occurring between childhood and adolescence. In contrast to her mentor and collaborator, Piaget, Inhelder took a much more process-oriented, functional approach to understanding thinking. The major change in thinking that occurs between childhood and adolescence involves the emergence of experimental or inductive thinking.

During a visiting appointment at Harvard University in 1961-1962, Inhelder was able to break away from the logical-structural approach of Piaget and focus on applying the functional approach to genetic epistemology. Several studies were conducted in an attempt to better understand the transition between various stages of development. The work of her and her collaborators culminated in a book entitled Learning and the Development of Cognition. They found that when children were in a transition between stages, training the children on concepts related to the next stage of development was successful in facilitating the promotion to the next stage.

Although Inhelder was pleased with the results regarding training, she was more interested in the fact that those studies also helped clarify the mechanisms for transition between stages. This finding became the foundation for Inhelder’s work on cognitive strategies and particularly children’s development of problem solving abilities. Instead of looking at broad, general strategies used by children, she again took a process-oriented approach and examined how and when children used specific procedures (which could be thought to add up to a strategy). This work provides information on the link between functional knowledge (know how) and structural knowledge (know that), which has been further explored by many cognitive psychologists.


  • The Diagnosis and Reasoning in the Mentally Retarded (1943)
  • The Psychology of the Child (1966, with Piaget)
  • Memory and Intelligence (1968, with Piaget)
  • Learning and the Development of Cognition (1974, with Sinclair and Bovet)

References: 5, 8, 14, 21, 28, 17